Profiles made of rolling stock are known in many diverse embodiments and production processes. Corresponding profiles are made starting from an essentially rectangular, oblong, flat metal strip normally by bending or rolling the metal band or strip. Here, “bending or rolling” comprise all processing steps that can be used to form the metal strip blank to the desired shape, e.g. also by U-bending, edge bending, embossing, etc. The flat metal strip can here be reshaped essentially without changing the material thickness, or reshaping can comprise methods in which a profile is produced of a metal strip whose cross-sectional surface does not comprise a constant thickness but intentionally has regions of greater and smaller material thickness.
One possible profile which is given here by way of example is e.g. a C-shaped assembly rail, as well as an anchor rail which is usually produced by hot rolling or cold-profiling. Hot-rolled profiles are here rolled from a steel ingot, wherein the heated steel ingot passes ca. 8 different rolls which each have several so-called passes through which the ingots are passed a varying number of times. In hot rolling, it is easily possible to form the profile preshape together with a reduction in thickness, where rolling for thickness reduction leads to the displaced material flowing laterally. In material-intensive profiles, such as C-profiles, the proportion of material costs is more than 70%, so that material savings drastically cut total costs.
As opposed to this, cold-profiled rails of steel strip are produced on rolls in one single operation where no thickness reduction takes place, as due to the friction transverse to the roll and the stiffness of the flat rolling stock, thickness reduction is only converted into stretching in the longitudinal extension or the direction of rolling, respectively, and material solidification.
A method for changing the thickness of a metal strip is e.g. known from DE 197 43 093. Here, a metal strip with a thinner strip formed within the same is produced, where the strip is pulled through a drawing nip which is formed by the front side of a working roll lined up at an angle and a backup roll which can be configured as working roll. While the strip is pulled through this nip, the two rolls exert a rolling force on the strip and simultaneously a pulling force transverse to the pulling direction, such that the displaced material in the regions to be thinned quasi exclusively flows transverse to the pulling direction.
Another method for the production of a metal strip with various thicknesses and in particular with a thicker edge is known from JP 55141330. Here, a light-metal strip is first guided through a pair of rolls, one roll being provided with end sections projecting beyond the actual rolling skin, and the second roll having a smaller width than the first roll and being arranged between the end sections of the first roll. If the light metal is guided through the roll nip, the material is displaced or flows towards the end sections which are in this manner formed to be thicker.